Growth comparison between post-larvae from cultured and wild spawners of Indian white shrimp, Penaeus indicus, in commercial farms in north Persian Gulf, Bushehr, Iran

Post larvae of wild and cultured spawners of the Indian white shrimp (Penaeus indicus, Milne Edwards, 1837) were reared to market size, in commercial ponds of shrimp farming site of Helleh, in Bushehr Province, during a six months period. Environmental factors, management process and the diet used to feed shrimps were almost similar for both treatments. Averages of the weight, length, specific growth rate, food conversion ratio and survival rate were measured and compared between the two treatments at harvesting time. Results indicated that, the post larvae of wild spawners had better growth, higher survival rate, and lower food conversion ratio. Weight gain of abdominal portion of the body, was higher in wild post larvae (P<0.01), which was in contrast to cephalothorax weight (P<0.01). Length-weight relationship measurements illustrated that, cultured post larvae obtained from wild spawners had similar size and were more acceptable for the market. Broodstock background could be the main reason for given differences, in which, those captured from the sea, had better condition due to receiving appropriate food with higher genetic diversity. To produce high quality post larvae for the expanding shrimp farming industry as an economic activity in the country, it is suggested that broodstocks to be obtained either from the sea as sub-adults or matured spawners, or to be provide from culturing shrimps, raised in conditions closest to the nature (i.e., ambient factors, prepared diets) and also with appropriate genetic diversity

Effect of different light regimes on the maturational progress of the whitespotted rabbitfish (Siganus sutor)

In this study, the effects of different light regimes on the reproductive activity of a typical Indo-Pacific coral reef rabbitfish, Siganus sutor, were evaluated. Forty-five adult fish were exposed to nine different photoperiod (8L: 16D, 12L: 12D, 16L: 8D) and light intensity (1000, 2000, 3000 lux) combinations with three replicates and five other fishes reared under indoor light condition (Control). Gonadosomatic Index (GSI) and Hepatosomatic Index (HSI) were calculated after 60 days and compared among different experimental regimes in males and females. In the control group, GSI and HSI mean values were 4.67 and 3.24%, respectively, for females and 10.05 and 2.10%, respectively, for males, and these fish showed differences in comparison with the exposed fish. Females kept under 1000 and 2000 lux light intensities had a higher GSI mean value (9.26 and 10.39%, respectively) and also lower average HSI (2.10 and 2.31%, respectively) in 16L: 8D treatment. A similar result was also obtained for males, whereas the 3000 lux light intensity, 8L: 16D day length combination led to more gonadal development (GSIs of 16.41% in females and 12.03% in males). A comparison of results among different photoperiods also confirmed that maturation was induced better in fish maintained under 16L: 8D in both sexes. This investigation revealed the visible role of both photoperiod and light intensity on inducing maturity in the whitespotted rabbitfish, S. sutor. Thus, rearing of adults exposed to an artificial light regime, including 16L: 8D and 2000 lux light intensity, promotes more gonadal development than that occurring in the wild

Comparative study of the effects of HUFA in dry diets and natural foods on fecundity and egg diameter of female broodstock of white leg shrimp (Litopenaeus vannamei)

During 2 months (from April to June, 2008) we studied the suitable quantity of Highly Unsaturated Fatty Acids (HUFA) for desirable fecundity and egg diameter of female broodstock of white leg shrimp (Litopenaeus vannamei). Similar dry food containing Isonitrogeneous material (31.5% protein) and Isolipid (6.9% lipid) was used but with different levels of HUFA (1, 2 and 3%). Also, the HUFA of natural foods (Perinereis worm, melalis bivalvia and cuttlefish) was analyzed. We compared the effects of four levels of dietary HUFA (1, 2 & 3 % HUFA of dry diets and the average HUFA of natural diets) on fecundity and egg diameter of female broodstock of white leg shrimp. The fecundity and egg diameter of natural diet and HUFA 3% were not significantly different (P>0.05). The fecundity of natural diet and HUFA 3% was significantly higher than the other two treatments (P<0.05) and also the egg diameter of HUFA 3% and natural diet was significantly higher than the other two treatments (P<0.05). According to the results of fecundity and egg diameter measurements, both natural and HUFA 3% diets are suggested as suitable for white leg shrimp breeding

Investigation on feeding behaviour of yellowfin seabream larvae, Acanthopagrus latus, fed on live food and microencapsulated diet

Feeding behavior of yellowfin seabream larvae during the first two weeks of larval life was studied by feeding larvae on different ratios of live food and microencapsulated diet (MED). Food consumption rate increased progressively with increasing larval weight. The results from visual observation of the larval guts under a light microscope indicated that yellowfin seabream larvae were able to ingest and digest MED from the onset of exogenous feeding. Comparing the average number of rotifers and MED ingested by larvae in treatments including either only live food or MED did not show any significant differences (P>0.05). In addition, the gut contents examination from the larvae fed simultaneously on both rotifer and MED, revealed that the larvae's tendency towards live food and/or MED was a function of live food density in the rearing tanks. The larvae preferentially ingest live food even when these are present at a very low concentration in comparison to MED. The mouth diameter of larvae has a strong influence on the amount of ingested rotifers and MED. There was a significant positive correlation between larvae growth and the average number of both live food and MED ingested by larvae in this trial (P0.05)

SOIL SPECTRAL PROPERTIES OF ARID REGION, KASHAN AREA, IRAN

This study determined some spectral characteristics and relationship between Landsat spectral reflectance and soil surface color in the arid region of Iran (Kashan). The study carried out in the kashan area that covers 90000 ha. Consisting of mountain, hills and flood plain. Enhanced Thematic Mapper (ETM+) data collected on July 2002 were used for this research. The color composite images produced from ETM+7, ETM+4 and ETM+2 as red, green and blue respectively used in order to choose sample sites. The twelve sample sites were chosen based on resampled 3*3 pixels (90*90 m). In each site, the soil surface conditions and the munsell color of the soil surface were investigated in the field. Some physico-chemical properties of soil samples were also determined in the laboratory. Soil surface particle sizes were categorized into three classes: bare soil 2mm in diameter and vegetated soil. The results of this study indicates that munsell notation of hue, value and chroma are significantly correlated to the visible bands of Landsat (ETM+) data. From this study it may be concluded that visible reflectance of Landsat can be used to estimate soil color, if very precise result is not expected .More investigation are necessary in order to improve the obtained results

Genetic variations of Iranian and French stocks of rainbow trout (Oncorhynchus mykiss)

Rainbow trout, Oncorhynchus mykiss is the most important cold water farmed fish as a nonindigenous species in Iran. Eyed eggs have been imported from different countries to Iran. In this study, genetic diversity of 50 fish (male and female) from Iranian generation and 24 fish from French generation were evaluated. Six microsatellite markers including OMM1019 ،OMM1036 ،OMM1307 ، OmyFGT5TU ،Omy77DU and Omy207UoG were applied. Average number of observed alleles in the Iranian and the French stocks were 6.68 and 6.83, respectively. Average number of effective alleles in the Iranian and French stocks were 3.13 and 3.45, respectively. Mean expected and observed heterozygosis was 0.68, 0.53 and 0.71, 0.61 in Iranian and French stocks, respectively. The results showed significant deviation from Hardy-Weinberg equilibrium at the most of loci × stock. Fixation index Fst calculated based on allelic frequency between two stocks was 0.058 with significant difference between 2 stocks. The results of this study showed insignificant genetic differentiation based on six microsatellite loci

Investigation of Litopenaeus vannamei culture in brackish waters of Bafgh, Yazd Province

This survey is part of the investigation on feasibility of introduction of Litopenaeus vannamei Boone, 1931 in shrimp culture industry of Iran. The objective was evaluation of the adaptation of the white leg shrimp, L. vannamei to brackish groundwaters of the Bafgh area in Yazd province. Around 120000 shrimp postlarvae (PL7 and 15) were stocked in four 0.15ha earthen ponds (17 and 23 ind/m ^(2)) in July 2005 and the culture period took about four months. Physicochemical and biological factors were studied during the culture. Shrimps were fed with commercial feed of the L. vannamei. Results showed low survival (19.2%) and growth (2-2.5g mean body weight). Based on the assessments, the limnological factors were most unfavorable elements causing the low growth in the shrimp. Concentration of K, Ca, Mg and Na Fe (II and III), different heavy metals, nitrogenous compounds, water hardness and the season and thermal periods are probably the most essential factors affecting production yield of the shrimp because of underground origin of the water. Also, the structure of ponds and drainages, presence of invasive water plants and insects may have affected the survival and growth of the shrimp as well

A Study on necessary infrastructures used for breeding trout in Yasoj region

Rainbow trout is the main cultural species of coldwater fishes in iran. Often, aquaculturists intend to breeding in order to production of lines with higher growth rate potential and disease resistant. Nevertheless in the country, no trout breeding programs, has been performed yet and most of the farms focused on the cultivation of the first(unbred) race. While European countries progressed in trout breeding techniques and production lines with higher growth through genetic manipulation (chromosomal number and type changes of fish) and/or selection and their fish products derived from this technology, including eyed eggs and so on have sold to other regions of the world(eg: Iran). In this study, some biological parameters including survival, growth, feed conversion ratio (FCR.) and chromosomal number of two juvenile groups from imported( group 1) and native(group 2) eyed fish eggs were compared. For chromosomal investigation, blood smear test and flow cytometry were performed. sults showed a significant difference (P≤5%) in growth rate of native fishes and French group Native fish feed conversion ratio (0.9) was significantly difference (P≤5%) from that of French fishes (1.15). Chromosomal analysis showed no difference in chromosome number in treatments and two fish groups were 2n chromosome. Based on the results, the fishes of group 1 had faster grow potential and gain weight in less time than that of group 2 and this has been achieved to go through the process of selection and feminization without any change in number of ploidy. Whereas the ability of native fishes in food efficiency ( lower FCR.) was better. However, the reduction of rearing period is the benefit and preference of cultivation of imported or origionally foreign

Determination of technical regulation & criteria of Iranian fisheries & marine aquatics

Accurate scientific and practical plan for achieving the goals of the Islamic Republic of Iran within the framework of Vision development 1404, is the infrastructure achieving sustainable development of the country. Order to achieve the above mentioned objectives and in order to the comprehensive development plans in the country, Iranian fisheries research organization adjust the fifth developing plan for support of executive related departments in country with mobilization a large number researchers consists of several working groups of IFRO affiliated research centers. The fifth developing plan consist of three chapters for report of the forth developing plan and intrudction of research , construction plans and financial support (budjet) for period of 2011-2014 A.C

Investigation possibility culture of shrimp Litopenaeus vannamei with brackish water of Caspian Sea in Mazandaran Province

Whiteleg shrimp (Litopenaeus Vannamei) is one of the most important species for aquaculture development, because of tolerance and adaptation to different ecological conditions. The aim of this study was determine the bionormative parameters of vannamei shrimp culture using Caspian Sea brakish water in Mazandaran province and also possibility of introduction a new aquatic species for rearing in Mazandaran province. The Shrimp vannamei reared with the brackish water (10±0.43ppt) of the Caspian Sea in Mazandaran province and the Caspian Sea Ecological Research Iinstitute in summer 1391, 1393 and 1394. In this study, were evaluated the effect of different densities (45/m^2, 50/m^2, 55/m^2 and 60/m^2) primary stock whiteleg shrimp postlarvae (PL12) on the growth, survival rate and also population structure of phytoplankton in shrimp vannamei. Initially, post larvae in brackish water were gradually adopted. The density of 35 per square pieces in an earthen pond (1000m^2) was stocking. The rearing time was 85 days. Average daily growths: 0.31±0.037g; final mean weight: 21.11±0.71; Feed conversion ratio: 0.79 and final yield: 531kg were determined. In addition the experiment of 1391, the results of Mazandaran province vannamei shrimp culture, were observed in 1393 and 1394, the average weight average daily growing and FCR % were 20-18 g and 0.68 - 0.77 respectively during 90 days culture period with harvesting of 40 PL /m^2 at cement culture pond. The experiments of effect of different densities were performed separately in 1391, in 12 circular concrete pound with a sandy bed (area: 78m^2) in the four treatments and three replications for each treatment. The experiments performed in a 75-day period. During the test, the water temperature was 27.4±1.79°C. The results showed that growth parameters and survival rate in experimental treatments, there was a statistically different (Duncan test, P<0.05). Thus, with high levels of density, the amount of weight gain and survival rate (SR), specific growth rate (SGR) and daily growth rate (ADG) has decreased. In addition, the treatments were different variations of FCR (P<0.05) and not depend on the primary stock density of postlarvae. The highest growth (SGR=11±0.04 and ADG=0.25±0.01) and survival rate and calculate the amount of production per hectare (5596±433) were observed in low density (45m2). In this study identified 20 genera of phytoplankton from five division of the Phytoplankton. Phylum Cyanophyta, with 30 percent of the identified genera that much more constituted. And the phylum Chlorophyta with 25 percent, of Bacillariophyta 20 percent Pyrrophyta 20 percent and Euglenophyta 5 percent had the lowest frequency. Chlorophyta with 25 percent allocated to the division, with 20 percent of Bacillariophyta, with 20 percent of the division; Pyrrophyta Euglenophyta division with 5 percent had the lowest frequency. Euglenophyta phylum was identified as a species. Therefore, based on acquired results, was observed that, vannamie shrimp was reared well using Caspian Sea brakish water in Mazandaran province. In addition, it seems that, vannamei shrimp was gained better results in Mazandaran province compared to other provinces, because of suitable water salinity